Tar Creek Catastrophe

The Tar Creek Superfund Site is an old mining site in the tiny town of Picher in Northeastern Oklahoma. The Tar Creek Superfund site is just one of many mining sites located in the Tri-State Mining District, which also includes Southeastern Kansas and Missouri. The Tri-State District produced 35% of all metals worldwide for over a decade and produced the majority of the lead bullets for World War II (1). While this doesn’t sound very catastrophic at first, a lot of events happened in Picher that made the place unsafe and virtually uninhabitable.

When the miners pulled all of the chat, a gravel like substance containing rock fragments, limestone, and toxic metals, from the mines, they left it in large piles all over the city instead of disposing of it properly. This caused heavy metals including lead to become abundant in the air, water, and topsoil all throughout Picher. What’s even worse is that Picher was part of the only reservation land left for the Quapaw Native American Tribe. After the forced removal of the Quapaw people from their land in the Mississippi Delta to Oklahoma, the state and federal governments worked together to pass a law that would allow for mining companies to obtain land in the Picher area. Because much of the land was owned by the Quapaw tribe, they found some really horrible ways to get around obtaining permission to seize Native American land. One of the legal loopholes that was created was a clause in the law which said that if the Secretary of the Interior found any of the Native Americans to be incompetent, the land would be released for mining. One of the locals stated that it turned out that most of the “incompetent” Native Americans were the ones that had mines on their property and were quarter-blood or more. Years later, when they started testing the blood lead levels of children in Picher, they began with testing the Quapaw children. Since then, many studies have shown that blood lead levels can have long lasting effects on both children and adults, but especially infants and toddlers. A small subset of these studies focuses directly on how the exposure of a child to lead during the gestational period affects postnatal growth and development.

In the Mothers and Children’s Environmental Health Study, 1150 pregnant women over the age of 18 and their offspring were evaluated to investigate the relationship between low-level prenatal lead exposure and postnatal growth as well as the role of calcium intake against the effects of lead exposure (2). This team found that even low blood lead levels, less than 5 micrograms per deciliter, were associated with reduced infantile growth all the way up to 24 months of age and that the lower the calcium intake, the more intense the effects of prenatal lead exposure on growth. This happens because in the case of a calcium deficiency, the calcium can be substituted with lead at the calcium binding sites in bone cells due to the similar size and charge of the two ions. This alters the functioning of many calcium binding proteins, including protein kinase C, as well as cell functions which depend on calcium such as the hormonal and local signal responses of the calcium messenger systems which disrupts the effects of both vitamin D3 and a parathyroid hormone that directly affect the development and regulation of bone mass.

Another study, performed by the National Institute of Perinatology in Mexico City, lead exposure around 28 weeks’ gestation is a very critical time for postnatal intellectual development with long lasting and possibly permanent effects (3). They studied 150 children from 12 weeks’ gestation to 6 years of age. During the last 13 weeks of gestation, the brain nearly triples in size. Around the 25th week, myelination of tracts has just begun in the fetal brain and the complete proliferation of neuroblasts is essentially complete by 28 weeks. This is because so much development occurs during a short period of time, they realized that children with a higher level of blood lead during the third trimester of pregnancy had a much lower IQ when they were six years old. They also note that there did not seem to be a specific blood lead threshold that had to be met to affect the child’s IQ, but rather the biggest effects came from low levels of lead exposure and that the effects are pretty obvious until at least 6 years of age, and maybe longer.

In the Oswego Children’s Study, it was determined that relatively low prenatal and postnatal blood lead levels identified by the Centers for Disease Control and Prevention for public health purposes can alter children’s adrenocortical responses to acute stress (4). The adrenal cortex is responsible for producing hormones that affect metabolism and the inflammatory response. Prenatal exposure had a significant effect on cortisol responses to acute stress at ages form birth up to 9.5 years of age, with increasing amounts of lead associated with an increasing cortisol response. Lead exposure has also been shown to affect the brain’s mesocorticolimbic dopaminergic system, which is more commonly known as the reward pathway in the brain. This can lead to what are sometimes referred to as “classroom problems” later in childhood such as irritability, lack of focus, and learning difficulties.

According to a former Picher resident a lot of the residents did not believe that lead was harmful for you and allowed their children to go play on the chat piles because they were fun (5). Due to this, a lot of women, who spent their whole lives in Picher playing in the chat piles and having picnics by the creek, that were beginning to raise families may have been passing lead from the environment to their children during their pregnancy without even realizing it. When Picher-Cardin Elementary School closed its doors in 2010, it served approximately 62 students, which shows that there were still a few young families living there around that time. These studies, and many others, have shown correlations between blood lead levels and some adverse effects, but lead poisoning can very hard to see and diagnose due to the internalized nature of the majority of signs and symptoms. While the city of Tar Creek now has only three residents left, the chat piles still remain.

1. Tar Creek [Film]; Jump the Fence Productions: Denver, CO, 2009.

2. Hong, Yun-Chul, et al. “Postnatal Growth Following Prenatal Lead Exposure and Calcium Intake.” Pediatrics, 24 Nov. 2014, vol. 134, no. 6, pp. 1151–1159., doi:10.1542.

3. Schnaas, L, Rothenberg, SJ, Flores, M-F, Martinez, S, Hernandez, C, Osorio, E, Velasco, SR & Perroni, E, “Reduced Intellectual Development in Children with Prenatal Lead Exposure.” Environmental Health Perspectives, 2006, vol. 114, pp. 791–797

4. Gump, B. B., Stewart, P., Reihman, J., Lonky, E., Darvill, T., Parsons, P. J., and Granger, D. A. (2008) Low-Level Prenatal and Postnatal Blood Lead Exposure and Adrenocortical Responses to Acute Stress in Children. Environmental Health Perspectives 116, 249–255.

5. Freeman, L., In person interview, February 2020